The genetic diversity of livestock is threatened worldwide, but especially in the global South, where the vast majority of farm animal breeds reside.

Documenting and conserving this diversity — of cattle, goats, sheep, swine and poultry — is just as essential as the maintenance of crop diversity for ensuring future food supplies in the face of health and environmental threats.

Just as we should know which crop varieties are most tolerant to flooding or disease, we should know which kinds of milking goat can bounce back quickly from a drought, which breeds of cow resist infection from sleeping sickness and which types of chicken can survive avian flu.

But while crop genes are being stored in thousands of collections across the world and a fail-safe genebank buried in the Arctic permafrost, no comparable effort exists to conserve livestock genes.

Dwindling diversity

About one-fifth of the world's 7,616 breeds of domestic livestock are at risk of extinction. For example, hardy Ankole cattle, raised across much of East and Central Africa, are being replaced by high-yielding Holstein-Friesian dairy cows and could disappear within the next 50 years.

In Vietnam, the proportion of indigenous sows dropped from 72 per cent in 1994 to just 26 per cent eight years later. In some countries, chicken populations have changed practically overnight from genetic mixtures of backyard fowl to selected uniform stocks raised under intensive conditions.

In the North, just six tightly defined breeds account for an astonishing 90 per cent of all cattle. A 2007 report by the Food and Agriculture Organization showed that over-reliance on a small number of livestock breeds is resulting in the loss of around one breed every month.

Most endangered livestock breeds are in developing countries, where they are herded by pastoralists or tended by farmers who grow both crops and livestock on small plots of land. Faced with a daily struggle to survive, many of these farmers are unlikely to prioritise conservation of their rare breeds — at least not without significant support.

A helping hand

From Africa to Asia, farmers of the South, like the farmers in Europe and the Americas before them, are increasingly choosing the breeds that will produce more milk, meat and eggs to feed their hungry families and raise their incomes.

They should be supported in doing so. But we cannot afford to altogether lose the breeds that are abandoned. These not only have intrinsic value, but many also possess genetic attributes critical to coping with threats such as climate change or emerging pests and diseases.

We urgently need policy support for their conservation. This means creating incentives that encourage farmers to keep traditional animals. For example, breeding programmes could boost the productivity of local breeds, or farmers' could be helped to access niche markets for traditional livestock products.

Policymakers must also consider the value of indigenous breeds when designing restocking programmes following droughts, disease epidemics, civil conflicts and other disasters that deplete herds.

A global effort

But even with help, poor farmers cannot stem all the diversity loss in farm animal breeds.

We need a parallel, even bigger effort, to link local, national and international resources and conserve livestock genetic diversity through dedicated livestock genebanks. These should store frozen cells, semen and DNA of endangered livestock from across the world.

The technology is available — cryopreservation has been used for years to aid both human and animal reproduction.

Genebanks should also be used to conserve the legacy of 10,000 years of animal husbandry. Collections must be accompanied by comprehensive descriptions of the animals and the populations from which they were obtained and the environments under which they were raised.

We must do all we can to assist farmers and herders to conserve the farm animal breeds that have largely been selected and nurtured into existence by generations of farmers attuned to their environments.

But if some of these treasured breeds fail to survive the coming decades of rapid agricultural development and climate change, we should at least have faithfully stored and recorded their presence, and have preserved their genes. It is these genes that will help us feed humanity and cope with unforeseen crises.

Carlos Seré is director-general of the International Livestock Research Institute in Nairobi, Kenya.

This article was updated 22 June 2010. A previous version of this article stated that the 2007 report by the FAO was published by the FAO and ILRI. This statement was incorrect.